1. Field of the Invention
The present invention relates to an eye gaze detection supporting device and an eye gaze detection supporting method.
2. Description of the Related Art
Eye gaze detection devices that detect a position that an operator or a subject is gazing at, on an observation surface such as a monitor screen, have been proposed. For example, methods that enable non-contact eye gaze detection are known, in which an eye gaze direction is reliably detected without attachment of any device to the face of the subject. In these methods, eye ball reflection of light irradiated from a light source is detected, a pupil center and a corneal curvature center are calculated, and a straight line that connects the pupil center and the corneal curvature center is detected as the eye gaze. In many of the methods, the eye ball reflection of light irradiated from two or more light sources is detected, and the eye gaze is calculated.
In the method of Patent Literature 1 (Japanese Patent No. 2739331), two cameras and two light sources are used, two corneal reflection points are detected in one eye ball, the corneal curvature center is calculated from the two corneal reflection points, and the eye gaze is detected from a positional relationship between the corneal curvature center and the pupil center. In the method of Patent Literature 2 (Japanese Patent No. 4824420), one camera and two light sources are used, the corneal curvature center is calculated from a line of intersection of planes respectively including the two corneal reflection points, and the eye gaze is detected from a positional relationship between the corneal curvature center and the pupil center.
However, the above-described methods of Patent Literatures have problems that a device configuration becomes complicated, and the size of the device becomes large. For example, when two light sources are used, two reflection points corresponding to the respective light sources are separately detected. Therefore, the distance between the two light sources needs to be separated by a predetermined distance or more. This is because, if the distance between the light sources is close, the two reflection points overlap with each other and separation becomes difficult.
Therefore, there is a need for an eye gaze detection supporting device and an eye gaze detection supporting method that can simplify the device configuration.